From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: DDoS attack causing bad effect on conntrack searches Date: Fri, 23 Apr 2010 12:35:41 +0200 Message-ID: <4BD177FD.9020904@trash.net> References: <1271941082.14501.189.camel@jdb-workstation> <1271943066.14501.194.camel@jdb-workstation> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Changli Gao , Eric Dumazet , Linux Kernel Network Hackers , netfilter-devel@vger.kernel.org, Paul E McKenney To: Jesper Dangaard Brouer Return-path: In-Reply-To: <1271943066.14501.194.camel@jdb-workstation> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Jesper Dangaard Brouer wrote: > I have added a stats counter to prove my case, which I think we should add to the kernel (to detect the case in the future). > The DDoS attack has disappeared, so I guess I'll try to see if I can reproduce the problem in my testlab. > > > > [PATCH] net: netfilter conntrack extended with extra stat counter. > > From: Jesper Dangaard Brouer > > I suspect an unfortunatly series of events occuring under a DDoS > attack, in function __nf_conntrack_find() nf_contrack_core.c. > > Adding a stats counter to see if the search is restarted too often. Applied, thanks Jesper.